Conventionally, as a flat thin display device, a liquid crystal display (LCD) device using a liquid crystal, a plasma display device using plasma, and the like have been put into practical use.
The LCD device is a display device in which a backlight device is installed, and an image is displayed such that when a voltage is applied, an arrangement of liquid crystal molecules changes to pass or block light from the backlight. The plasma display device is a display device that displays an image such that a voltage is applied to a gas sealed in a substrate to create a plasma state, and ultraviolet light generated by energy generated when an original state is returned from the plasma state is irradiated to a luminous body and thus converted to visible light.
Meanwhile, in recent years, a light-emitting type display device using an organic electroluminescence (EL) device in which a device itself emits light when a voltage is applied has been developed. The organic EL device changes from a ground state to an excited state when energy is received by electrolysis and emits energy of a difference as light when the ground state is returned from the excited state. An organic EL display device displays an image using light emitted from the organic EL device.
Unlike the LCD device that requires the backlight, the light-emitting type display device does not require the backlight since the device emits light by itself. Thus, the light-emitting type display device can be configured thinner than the LCD device. Further, compared to the LCD device, the organic EL display device is excellent in a moving image characteristic, a viewing angle characteristic, color reproducibility, and the like and thus has attracted attention as a next generation flat thin display device.
However, in the organic EL device, when a voltage is continuously applied, an emission characteristic deteriorates, and even if the same current is input, brightness deteriorates. As a result, when an emission frequency of a certain pixel is high, the certain pixel is inferior in the emission characteristic as compared to the other pixels, and a phenomenon known as “burn-in” has been a problem.
The burn-in phenomenon occurs even in the LCD device or the plasma display device. In these display devices, since an image is displayed by applying an alternating current voltage, there has been a need for a means for adjusting the applied voltage. On the other hand, in the light-emitting type display device, a technique of correcting the burn-in by controlling a current amount has been employed. For example, a burn-in correction technique in the light-emitting type display device is disclosed in Patent Literature 1.